01 Sintra & Pena Palace
The one Lisbon ticket that genuinely needs planning, from €29. Pena Palace sells timed entry and the mid-morning slots go days ahead from May to September; Quinta da Regaleira next door does not, which is why most small-group tours pair them. Sintra is a hill town with one road, so going by organised trip rather than by train and taxi is the difference between three sites and one.
02 Belém
Cheap to enter and slow to reach: the monastery, the tower and the pastry shop are all within a few hundred metres, and the queue is at the pastry shop. Go early, take the tram out and the ferry or an e-bike back. Tickets are usually available on the day outside August.
03 Alfama & the Fado houses
Not a ticket so much as an evening. The fado houses that admit walk-ins are the ones the guides avoid; anything worth hearing takes a booking, usually with dinner attached. Combined food-and-fado walks rate well here because they solve the ordering problem for you.